Manchester United insist midfielder Nicky Butt will not leave the club as part of a swap deal.
The 28-year-old has put in a transfer request in a bid to find regular first-team football, with Middlesbrough reportedly favourites to sign him.
Speculation had been mounting that Butt would move, with Boro defender Gareth Southgate heading to Old Trafford.
But United are now believed to want to sell the player to raise funds to sign Fulham striker Louis Saha.
Butt has been at United for 11 years but now looks destined for a move elsewhere, with Boro facing competition from Tottenham, Newcastle, Everton and Birmingham.
Manager Sir Alex Ferguson told The Sun newspaper on Tuesday: "Nicky Butt has asked to leave. It is a very sad situation.
"With Phil Neville, and the emergence of Darren Fletcher and Kleberson, it has made it difficult to get in the team so he has asked to leave.
"Nicky has given Manchester United great service but he wants to play
first-team football."
Butt is expected to cost in the region of £5m.
Spurs are thought to be looking for a combative midfielder while Boro boss Steve McClaren worked closely with the player during his own time at United.
"He would be the perfect player for us," McClaren claimed before Christmas.
"If there was any possibility of getting him I would be first on the phone."
Born in Manchester, Butt was one of the famed 'Class of 92' which won the FA Youth Cup, alongside Ryan Giggs, Gary Neville, Paul Scholes and David Beckham.
He was the first from that group to break into Ferguson's first-team squad the same year, and was also a key figure last season, returning from an ankle injury to help United to the Premiership title.
But following an operation on that troublesome ankle in the summer, this campaign has seen him start only 11 of United's 31 competitive matches.